Vacuum cleaner with agitator assembly incorporating a clutch mechanism

ABSTRACT

An upright vacuum cleaner includes a housing having a handle assembly pivotally connected to a nozzle assembly. A suction generator and dirt collection vessel are carried on the housing. The suction generator includes a drive motor. A rotary agitator assembly and a suction inlet are carried on the nozzle assembly. The rotary agitator assembly includes an axle, a drive pulley mounted on the axle, an agitator body mounted on the axle and a clutch assembly. The clutch assembly includes a first clutch element, a second clutch element, a first biasing spring, a second biasing spring and an actuator that allows the operator to selectively engage and disengage the clutch assembly.

INCORPORATING A CLUTCH MECHANISM

This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/977,502 filed on 4 Oct. 2007.

TECHNICAL FIELD

The present invention relates generally to the floor care equipment field and, more particularly, to an upright vacuum cleaner equipped with ah agitator including a clutch assembly that, allows interruption of drive to the agitator for bare floor cleaning.

BACKGROUND OF THE INVENTION

A vacuum cleaner is an electro-mechanical appliance utilized to effect the dry removal of dust, dirt and other small debris from carpets, rugs, fabrics or other surfaces in domestic, commercial and industrial environments. In order to achieve the desired dirt and dust removal, most vacuum cleaners incorporate a rotary agitator. The rotary agitator is provided to beat dirt and debris from the nap of the carpet or rug while a pressure drop or vacuum is used to force air entrained with this dirt and debris into the nozzle of the vacuum cleaner. The particulate laden air is then drawn into a dirt collection vessel. The air is then drawn through a filter before being directed through the motor of the suction generator to provide cooling. Finally, the air is filtered to remove any fine particles of carbon from the brushes of that motor or other dirt that might remain in the air-stream before being exhausted back into the environment.

While, a rotary agitator is particularly beneficial in cleaning dirt and debris from the nap of a carpet or rug. It has long been known that the turbulence produced by a rapidly rotating agitator often interferes, with the efficient cleaning of dirt and debris from a bare floor such as a hardwood or linoleum covered floor. Thus, for bare floor cleaning applications it is desirable to interrupt power to the rotary agitator. Where an upright vacuum cleaner incorporates a separate drive motor for the agitator, this is easily accomplished by simply de-energizing that dedicated drive motor. However, in order to lower production costs, minimize weight and reduce the size of an upright vacuum cleaner, many upright vacuum cleaners drive the rotary agitator through a power takeoff connected to the motor of the suction generator.

The interruption of the drive between the motor of the suction generator and the rotary agitator has taken many forms. Often, power is transmitted from the drive shaft of the suction generator motor to the agitator by means of a belt. In one approach a belt shifter is provided to shift the belt between the agitator drive pulley and an idler pulley to interrupt power transmission to the agitator. An example of just such an approach is disclosed in U.S. Pat. No. 5,768,746 to Kamatani et al. In yet another approach, an idler pulley is utilized to tension the drive belt to provide drive to the agitator and de-tension the drive belt to interrupt drive to the agitator. Such an approach is disclosed in, for example, U.S. Pat. No. 5,537,712 to Weber et al. and U.S. Pat. No. 6,915,544 to Roney et al.

In still another approach a displaceable belt shaft is provided to disengage the drive belt from the drive shaft of the suction generator motor when it is desired to interrupt power to the agitator. Such an approach is disclosed in U.S. Pat. No. 6,098,243 to Kim. In yet another approach, power is transmitted by a belt from the drive shaft of the suction generator drive motor to a pulley adjacent and axially aligned with the agitator. A first clutch disc is provided on the pulley and a second clutch disc is provided on the agitator. The clutch discs are engaged arid disengaged by shifting the pulley toward and away from the agitator.

The present invention relates to an agitator equipped with a clutch assembly that may be disengaged to interrupt power to the rotary agitator without tensioning, stretching or otherwise manipulating the drive belt or any of the pulleys to which the drive belt is connected.

SUMMARY OF THE INVENTION

In accordance with the purposes of the present invention as described herein, an upright vacuum cleaner comprises a housing including a handle assembly pivotally connected to a nozzle assembly. The nozzle assembly includes a suction inlet. A suction generator and dirt collection vessel are both carried on the housing. The suction generator includes a drive motor.

In addition, a rotary agitator assembly is carried on the nozzle assembly. The rotary agitator assembly includes an axle, a drive pulley mounted on the axle, an agitator body mounted on the axle and a clutch assembly. The clutch assembly includes a first clutch element carried on the drive pulley, a second clutch element carried on the agitator body, a first spring biasing the first and second clutch elements apart with a biasing force F₁, a second spring biasing the first and second clutch elements together with a biasing force F₂, a spring holder holding the second spring and an actuator to selectively engage or displace the spring holder and thereby disengage the clutch assembly and interrupt drive to the agitator body. The biasing force F₂ of the second spring element is greater than the biasing force F₁ of the first spring element so that the clutch assembly is normally engaged in order to provide rotary drive to the agitator body.

More specifically describing the invention, the agitator body includes a first end cap at a first end and a second end cap at a second end. A first bearing assembly is held in the first end cap. A second bearing assembly is held in the second end cap. The first and second bearing assemblies allow the agitator assembly to rotate freely on the axle. A third bearing assembly is held in the drive pulley. The third bearing assembly allows the pulley to rotate freely on the axle.

A first mounting block is provided at the first end of the axle. A second mounting block is provided at a second end of the axle. The axle is mounted to the nozzle assembly by means of the mounting blocks. In addition, the actuator is carried by the second mounting block.

The spring holder includes a flange and the actuator includes a cooperating cam. The cam includes a sloped surface that engages the flange on the spring holder. The actuator is displaceable between a first position out of engagement with the flange wherein the clutch assembly is engaged and the agitator body is driven and a second position wherein the actuator engages the spring holder and the clutch assembly is disengaged and drive to the agitator body is interrupted.

In accordance with additional aspects of the present invention, a dirt collection vessel may take the form of a dirt cup. In one possible embodiment the dirt cup includes a cylindrical sidewall, a tangentially directed inlet and an axially directed outlet. In yet another possible embodiment a primary filter is received in the dirt cup over the axially directed outlet. In still another possible embodiment the dirt collection vessel takes the form of a filter bag.

In the following description there is shown and described a preferred embodiment of this invention, simply by way of illustration of some of one of the modes best suited to carry out the invention. As it will be realized, the invention is capable of other different embodiments and its several details are capable of modification in various, obvious aspects all without departing from the invention. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings incorporated herein and forming a part of the specification, illustrate several aspects of the present invention and together with the description serve to explain certain principles of the invention. In the drawings:

FIG. 1 is a perspective view of the vacuum cleaner of the present invention;

FIG. 2 is a detailed schematical view of one possible embodiment wherein the dirt collection vessel of the vacuum cleaner incorporates a cylindrical side wall, a tangentially directed inlet, an axially directed outlet and a primary filter;

FIG. 3 is an exploded perspective view of the rotary agitator assembly including the drive pulley and the clutch assembly of the present invention;

FIG. 4 is a detailed cross sectional view illustrating the rotary agitator assembly when the clutch assembly is in the engaged position;

FIG. 5 is a cross-sectional view similar to FIG. 4 but illustrating the clutch assembly in the disengaged position; and

FIG. 6 is a detailed perspective view illustrating how the actuator is received in the track on the second mounting block.

Reference will now be made in detail to the present preferred embodiments of this invention, examples of which are illustrated in the accompanying drawings.

DETAILED DESCRIPTION OF THE INVENTION

Reference is now made to FIG. 1 showing the upright vacuum cleaner 10 of the present invention. The upright vacuum cleaner 10 includes a housing comprising a nozzle assembly 14 and a handle or handle assembly 16. The handle assembly 16 further includes a control handle 18 and a handgrip 20. A control switch 22 is provided for turning the vacuum cleaner 10 on and off. Of course, electrical power is supplied to the vacuum cleaner 10 from a standard electrical wall outlet through an electrical cord (not shown).

A pair of rear wheels (not shown) are provided on the lower portion of the handle assembly 16 and a pair of front wheels (also not shown) are provided on the nozzle assembly 14. Together, these wheels support the vacuum cleaner 10 for movement across the floor. To allow for convenient storage of the vacuum cleaner 10, a foot latch 30 functions to lock the canister assembly in an upright position as shown in FIG. 1. When the foot latch 30 is released, the handle assembly 16 may be pivoted relative to the nozzle assembly 14 as the vacuum cleaner 10 is manipulated back and forth to clean the floor.

In the presently illustrated embodiment, the handle assembly 16 includes a cavity adapted to receive and hold the dirt collection vessel 32. As illustrated in FIG. 2, the dirt collection vessel 32 may take the form of a dirt cup 34 including a cylindrical sidewall 36, a tangentially directed inlet-38 and an axially directed outlet 40. A primary filter 42 may be provided in the dirt cup 34 over the axially directed outlet 40. The primary filter 42 is cylindrical in shape and concentrically received within the cylindrical sidewall 36 of the dirt cup 34. Such a structural arrangement induces cyclonic airflow in the dirt cup 34 and provides for enhanced cleaning efficiency. In an alternative design, the handle assembly 16 includes a closed compartment that houses a filter or vacuum cleaner bag, of a type known in the art, that functions as the dirt collection vessel 32.

The nozzle assembly 14 includes a suction inlet 44. A rotary agitator assembly 46 is carried on the nozzle assembly 14 so as to extend across the suction inlet 44. A suction generator 48, including a fan and a cooperating drive motor, is carried on the handle assembly 16. The suction generator 48 functions to generate a vacuum air stream for drawing dirt and debris from the surface to be cleaned. The rotary agitator assembly 46 is connected by power take off to the motor of the suction generator 48. While the suction generator 48 is illustrated as being carried on the handle assembly 16, it should be appreciated that, alternatively, it could be carried on the nozzle assembly 14 if desired.

During normal vacuum cleaner operation, the rotary agitator 46 is driven by the motor 50 of the suction generator 48 and functions to beat dirt and debris from the nap of an underlying carpet. The suction generator 48 functions to draw a vacuum air stream into the suction inlet 44. Dirt and debris from the carpet is entrained in the air stream, which is then drawn by the suction generator 48 into the dirt cup 34. Dirt and debris is captured in the dirt cup 34 while relatively clean air is drawn through the primary filter 42. That air stream then passes over the motor 50 of the suction generator 48 to provide cooling before being exhausted through a final filter, such as a HEPA filter (not shown) before being exhausted through an exhaust port 37 into the environment.

The agitator assembly 46 of the present invention is illustrated in detail in FIGS. 3-5. The agitator assembly 46 includes an agitator body 52 that carries bristles, brushes, beater bars, membranes or other cleaning elements (not shown) of a type known in the art. The agitator body 52 is tubular and incorporates a first end cap 54 at one end and a second end cap. 56 at the other end. The first end cap 54 receives and holds a first bearing assembly 58 while the second end cap 56 receives and holds a second bearing assembly 60. The agitator body 52 is received over and carried on an axle 62 (note also the retaining nut 63). More specifically, the first and second bearing assemblies 58, 60 allow the agitator body to freely rotate on the axle 62.

As further illustrated in FIGS. 3-5, a pulley 64 includes a third bearing assembly 66 (two bearing units and a spacer). Like the agitator body 52, the pulley 64 is mounted on the axle 62. The third bearing assembly 66 ensures that the pulley 64 freely rotates on the axle 62. The pulley 64 is connected by a belt (not shown) to the drive shaft of the motor of the suction generator 48. The axle 62 is secured in the nozzle assembly 14 by means of first and second mounting blocks 68, 70. More specifically, each mounting block 68, 70 is received in a cooperating pocket or socket that is integrally molded as part of or is otherwise fixed to the housing of the nozzle assembly 14 in a manner known in the art.

The agitator assembly 46 also includes a clutch assembly 100. The clutch assembly 100 includes a first clutch element 72 connected to the pulley 64 and a cooperating second clutch element 74 connected to the second end cap 56 of the agitator body 52. As clearly illustrated, each clutch element 72, 74 includes a contact surface that is frustoconical in shape. Such structures provide a larger mating surface area when the clutch assembly 100 is engaged to drive the agitator body 52 as illustrated in FIG. 4. This enhances operating efficiency, resists slipping and ensures a long service life. The second clutch element 74 may be formed from a rubber material in order, to provide maximum adhesion with the first clutch element 72 when the clutch assembly 100 is engaged.

A first compression spring 76 received over the axle 62 and extending between the first end of the agitator body 52 and the pulley 64 functions to bias the second clutch element 74 and agitator body 52 away from the first clutch element 72 with a biasing force F₁ (note action arrow A). A second compression spring 78 received over the axle 62 and extending between the second mounting block 70 and the second end of the agitator body 52 is received in a spring holder 80. The second spring 78 functions to bias the second clutch element 74 and the agitator body 52 toward the first clutch element 72 and the pulley 64 with a biasing force F₂ (note action arrow B). The biasing force F₂ of the second spring 78 is greater than the biasing force F₁ of the first spring 76. As a result, the agitator body 52 is normally shifted longitudinally along the axle 62 in the direction of action arrow B with the two clutch elements 72, 74 fully engaged as illustrated in FIG. 4. In this position, drive is provided from, the pulley 64 to the agitator body 52, which is rotated around the axle 62 to beat dirt and debris from the nap of an underlying carpet to be cleaned.

The clutch assembly 100 further includes an actuator generally designated by reference numeral 82. The actuator 82 includes a lever arm 84 connected to a forked end including two prongs 86. The end of each prong 86 includes an inclined cam surface 88. The spring holder 80 includes an outwardly projecting flange 90. The actuator 82 is received for sliding movement in a guide track 92 provided on the second mounting block 70. When the actuator 82 is provided in a first, retracted position, the cams 88 at the end of the prongs 86 are just clear of engagement with the flange 90 on the spring holder 80. As a consequence, the second spring 78 exerts a biasing force F₂ in the direction of action arrow B on the agitator body 52. The biasing force F₂ is greater than the biasing force F₁ exerted by the first spring 76 in the direction of action arrow A. Accordingly, the agitator body 52 translates longitudinally along the axle 62 in the direction of action arrow B until the clutch element 74 is fully seated on the clutch element 72. As a consequence, the clutch assembly 100 is engaged and the agitator body 52 is rotated about the axle 62 by the motor of the suction generator 48.

When the operator slides the actuator 82 along the track 92 into the second, extended position, the cams 88 at the end of the prongs 86 engage the flange 90 on the spring holder 80. The inclined surface of the cams 88 serves to force the spring holder 80 toward the second mounting block 70 against the biasing force of the second spring 78. As a consequence, the biasing force F₁ of the first spring 76is unopposed and the agitator body 52 translates under that force along the axle 62 in the direction of action arrow A. As a consequence, the clutch elements 72, 74 are separated and the clutch assembly 50 is disengaged. This serves to interrupt drive to the agitator body 52, which is then stationary on the axle 62. In this position the operator may use the vacuum cleaner 10 to efficiently clean a bare floor.

The foregoing description of the preferred embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments were chosen and described to provide, the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which, they are fairly, legally and equitably entitled. The drawings and preferred embodiments do not and are riot, intended to limit the ordinary meaning of the claims, in their fair and broad interpretation in any way. 

1. An upright vacuum cleaner, comprising: a housing including a handle assembly pivotally connected to a nozzle assembly, said nozzle assembly including a suction inlet; a suction generator carried on said housing, said suction generator including a drive motor; a dirt collection vessel carried on said housing; and a rotary agitator assembly carried on said nozzle assembly, said rotary agitator assembly including an axle, a drive pulley mounted on said axle, an agitator body mounted on said axle and a clutch assembly; said clutch assembly including a first clutch element carried on said drive pulley, a second clutch element carried on said agitator body, a first spring biasing said first and second clutch elements apart with a biasing force F₁, a second spring biasing said first and second clutch elements together with a biasing force F₂, a spring holder holding said second spring and an actuator to selectively engage and displace said spring holder and thereby disengage said clutch assembly and interrupt drive-to said agitator body.
 2. The vacuum cleaner of claim 1, wherein said, biasing force F₂ of said second spring is greater than said biasing force F₁ of said first spring.
 3. The vacuum cleaner of claim 2, wherein said agitator body includes a first end cap at a first end and a second end cap at a second end.
 4. The vacuum cleaner of claim 3, further including a first bearing assembly held in said first end cap and a second bearing assembly held in said second end cap, said first and second bearing assemblies allowing said agitator body to rotate freely on said axle.
 5. The vacuum cleaner of claim 4, further including a third bearing assembly held in said drive pulley, said third bearing assembly allowing said drive pulley to rotate freely on said axle.
 6. The vacuum cleaner of claim 5, further including a first mounting block at a first end of said axle and a second mounting block at a second end of said axle.
 7. The vacuum cleaner of claim 6, wherein said actuator is carried by said second mounting block.
 8. The vacuum cleaner of claim 7, wherein said spring holder includes a flange and said actuator includes a cam.
 9. The vacuum cleaner of claim 8, wherein said cam includes a sloped surface that engages said flange or said spring holder.
 10. The vacuum cleaner of claim 9, wherein, said actuator is displaceable between a first position out of engagement with said flange wherein said clutch assembly is engaged and said agitator body is driven and a second position wherein, said clutch, assembly is disengaged and drive to said agitator body is interrupted.
 11. The vacuum cleaner of claim 1, wherein said dirt collection vessel is a dirt cup.
 12. The vacuum cleaner of claim 11, wherein said dirt cup includes a cylindrical sidewall, a tangentially directed inlet and an axially directed outlet.
 13. The vacuum cleaner of claim 12, further including a primary filter received in said dirt cup over said axially directed outlet.
 14. The vacuum cleaner of claim 1, wherein said dirt collection vessel is a filter bag.
 15. The vacuum cleaner of claim 1, wherein said second clutch element is made from rubber. 